1. Field of the Invention
The present invention relates to a wall lamp, and particularly to a wall lamp using light emitting diodes as a light source and having a heat sink on which the light emitting diodes are mounted whereby heat generated by the light emitting diodes can be dissipated by the heat sink.
2. Description of Related Art
Electronic component includes numerous circuits operating at high speed and generating substantive heat. In many applications, it is desirable to employ a heat sink to remove heat from heat-generating electronic components, for example, LED components in an LED lamp, to assure that the components function properly and reliably.
An LED lamp is a type of solid-state lighting device that utilizes light-emitting diodes (LEDs) as a source of illumination. An LED is a device for converting electricity into light by using a theory that, if a current is made to flow in a forward direction through a junction region comprising two different types of semiconductor, electrons and holes are coupled at the junction region to generate a light beam. The LED has an advantage that it is resistant to shock, and has an almost eternal lifetime under a specific condition; thus, the LED lamp is intended to be a cost-effective yet high quality replacement for incandescent and fluorescent lamps.
An LED lamp generally has a limited space therein and requires a plurality of LEDs. Most of the LEDs are driven at the same time, which results in a quick rise in temperature of the LED lamp. Since the limited space in the LED lamp, the heat sink has a restricted heat dissipating area and is unable to remove heat from the LEDs effectively. Operation of the conventional LED lamps thus has a problem of instability because of the rapid buildup of heat.
Besides, since an illuminant angle of the light emitted by the LEDs is generally restricted in a narrow range and the LEDs are mounted on a flattened surface of the heat sink, the light of the conventional LED lamp is of unsatisfactory spatial distribution and cannot meet users' requirement.
What is needed, therefore, is an LED lamp which has a heat sink with a great heat dissipating capability in a limited space. Furthermore, the heat sink applied in the LED lamp has a such design that the LED lamp can provide a wide illumination angle.